scholarly journals An anterior sauropod caudal from the Peterborough Oxford Clay: Whose tail is it anyway?

Author(s):  
Femke M Holwerda ◽  
Jeff J Liston

The Callovian Oxford Clay of England has yielded a rich and diverse marine fauna, mainly discovered and described by Alfred Leeds. However, occasionally it also brought forth terrestrial fossils, including four isolated cases of sauropod remains, one of a stegosaurid, and another of a dryosaurid. Thus far, only Cetiosaurus oxoniensis and Cetiosauriscus stewarti are confirmed sauropod taxa from these beds. Here, we describe an isolated sauropod anterior caudal vertebra from the Oxford Clay near Peterborough. Incomplete, it has been immersed in seawater post-mortem, indicated by the adhesion of molluscs, but some characters can nevertheless be used for diagnosis and comparisons. The anterior articular surface is round, whereas the posterior articular surface is heart- shaped, as in many eusauropods, including Cetiosaurus. Interestingly, the ventral surface shows a keel-like structure; a character shared with neosauropods (e.g. Barosaurus) but also with an as yet unnamed Middle Jurassic sauropod caudal from York, UK. The posterior side of the neural canal is teardrop-shaped, a character shared with most basal eusauropods. Below the posterior neural canal, a lip-like structure seems to be present; a character which is shared with Cetiosaurus. However, the anterior caudal transverse process (ACTP) complex is similar to, although more pronounced than Cetiosauriscus, being more similar to more derived sauropods (Neosauropoda). Thus, an incomplete isolated element may help elucidate sauropod species diversity and dispersal in the Middle Jurassic of England.

2017 ◽  
Author(s):  
Femke M Holwerda ◽  
Jeff J Liston

The Callovian Oxford Clay of England has yielded a rich and diverse marine fauna, mainly discovered and described by Alfred Leeds. However, occasionally it also brought forth terrestrial fossils, including four isolated cases of sauropod remains, one of a stegosaurid, and another of a dryosaurid. Thus far, only Cetiosaurus oxoniensis and Cetiosauriscus stewarti are confirmed sauropod taxa from these beds. Here, we describe an isolated sauropod anterior caudal vertebra from the Oxford Clay near Peterborough. Incomplete, it has been immersed in seawater post-mortem, indicated by the adhesion of molluscs, but some characters can nevertheless be used for diagnosis and comparisons. The anterior articular surface is round, whereas the posterior articular surface is heart- shaped, as in many eusauropods, including Cetiosaurus. Interestingly, the ventral surface shows a keel-like structure; a character shared with neosauropods (e.g. Barosaurus) but also with an as yet unnamed Middle Jurassic sauropod caudal from York, UK. The posterior side of the neural canal is teardrop-shaped, a character shared with most basal eusauropods. Below the posterior neural canal, a lip-like structure seems to be present; a character which is shared with Cetiosaurus. However, the anterior caudal transverse process (ACTP) complex is similar to, although more pronounced than Cetiosauriscus, being more similar to more derived sauropods (Neosauropoda). Thus, an incomplete isolated element may help elucidate sauropod species diversity and dispersal in the Middle Jurassic of England.


2019 ◽  
Vol 7 ◽  
Author(s):  
Yin Cheong Aden Ip ◽  
Ywee Chieh Tay ◽  
Su Xuan Gan ◽  
Hui Ping Ang ◽  
Karenne Tun ◽  
...  

Few tropical marine sites have been thoroughly characterised for their animal species, even though they constitute the largest proportion of multicellular diversity. A number of focused biodiversity sampling programmes have amassed immense collections to address this shortfall, but obstacles remain due to the lack of identification tools and large proportion of undescribed species globally. These problems can be partially addressed with DNA barcodes (“biocodes”), which have the potential to facilitate the estimation of species diversity and identify animals to named species via barcode databases. Here, we present the first results of what is intended to be a sustained, systematic study of the marine fauna of Singapore’s first marine park, reporting more than 365 animal species, determined based on DNA barcodes and/or morphology represented by 931 specimens (367 zooplankton, 564 macrofauna including 36 fish). Due to the lack of morphological and molecular identification tools, only a small proportion could be identified to species solely based on either morphology (24.5%) or barcodes (24.6%). Estimation of species numbers for some taxa was difficult because of the lack of sufficiently clear barcoding gaps. The specimens were imaged and added to “Biodiversity of Singapore” (http://singapore.biodiversity.online), which now contains images for > 13,000 species occurring in the country.


Zootaxa ◽  
2019 ◽  
Vol 4590 (2) ◽  
pp. 201
Author(s):  
CHRISTINE M. KAISER ◽  
MARK O’SHEA ◽  
HINRICH KAISER

We describe a new species of Indo-Papuan groundsnake (Stegonotus) from a single adult male specimen collected in 1953 near Kamro, a village in Maybrat Regency, West Papua, Indonesia. The specimen had been considered a member of S. batjanensis, a well-defined species from the northern Maluku Islands over 500 km to the northwest with which it shares the key characteristic of having the 3rd, 4th, and 5th supralabial scales touching the eyes. The new species can be differentiated from S. batjanensis as well as all other species of Stegonotus by having its 5th supralabial scale projecting forward from behind the eye to form a narrow contact zone with the eye. In addition, it is differentiated by the combination of the following characteristics: seven supralabials, the 3rd–5th touching the eye; eight infralabials, the 1st–4th touching the anterior genial; four scales separating the posterior genial and the first gastrostege; dorsal scales in 17 rows, diminishing to 15 posteriorly; a low number of ventrals (181 in the holotype) combined with a high number of subcaudals (105 in the holotype), the latter comprising 37% of the scales on the ventral surface, the highest proportion in the genus. The description of this species is of interest beyond adding to the species diversity of Stegonotus: it allowed us to explore additional characteristics to resolve taxonomic questions in a morphologically conservative genus, it illustrates the need for additional herpetological survey work on the Bird’s Head Peninsula, and its initial misidentification serves as a reminder of the continued relevance and importance of natural history collections as repositories for specimens and data that influence our knowledge today by reaching out from the past.


2015 ◽  
Vol 84 (3) ◽  
pp. 179-191 ◽  
Author(s):  
Ninon Robin ◽  
Barry W.M. van Bakel ◽  
Jean-Loup d’Hondt ◽  
Sylvain Charbonnier

The earliest known crabs are of Early and Middle Jurassic age; in general, they are rare. Here we describe a new species of homolodromioid from the late Bathonian of Sarthe (France), based on a single dorsal carapace, Tanidromites raboeufi n. sp. This specimen has mostly well-preserved cuticle, and shows two episkeletozoans (bryozoan colonies) on its dorsal side, which is unique amongst early brachyurans (Early and Middle Jurassic). These bryozoans are identified as juvenile colonies of the morphogenus Berenicea (sheet-like tubuluporines), typical encrusters of hard substrates. Their presence directly on the carapace crab shows that they were closely cohabitating with this early brachyuran in its palaeoenvironment. One of these colonies appears to have attached to the internal carapace surface, indicative of post-mortem settlement and growth. Colony sizes suggest a growth phase of at least several months on the sea floor, implying a certain resistance to decomposition of the crab carapace. This is of note in the light of extant homolodromioids which are known to have extremely fragile carapaces. This association demonstrates that post-mortem associations may yield palaeoecological insights into both substrate and colonising organisms.


2012 ◽  
Vol 153 (1) ◽  
pp. 119 ◽  
Author(s):  
Gabriel Lio ◽  
Federico Agnolin ◽  
Andrea Cau ◽  
Simone Maganuco

<em>Kemkemia auditorei</em> Cau &amp; Maganuco, 2009 was recently described as a new genus and species of theropod dinosaur on the basis on an isolated distal caudal vertebra. The holotype and only known specimen comes from Kem Kem beds (Upper Cretaceous) of Morocco. In the present paper we review the phylogenetic position of <em>Kemkemia</em> and we conclude that this taxon belongs to Crocodyliformes. It shares with crocodyliforms the presence of a concavity at the posterolateral margin of neural spines, an inflated neural canal, and reduced prezygapophyses, among other traits. This combination of characters clearly distinguishes <em>Kemkemia</em> from theropod dinosaurs. In this way, <em>Kemkemia</em> is here considered as a Crocodyliformes <em>incertae sedis</em>, and based on the absence of unique characters, the genus and species <em>Kemkemia</em> auditorei is proposed as a nomen <em>dubium</em>.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6404
Author(s):  
Femke M. Holwerda ◽  
Mark Evans ◽  
Jeff J. Liston

Four isolated sauropod axial elements from the Oxford Clay Formation (Callovian, Middle Jurassic) of Peterborough, UK, are described. Two associated posterior dorsal vertebrae show a dorsoventrally elongated centrum and short neural arch, and nutrient or pneumatic foramina, most likely belonging to a non-neosauropod eusauropod, but showing ambiguous non-neosauropod eusauropod and neosauropod affinities. An isolated anterior caudal vertebra displays a ventral keel, a ‘shoulder’ indicating a wing-like transverse process, along with a possible prespinal lamina. This, together with an overall high complexity of the anterior caudal transverse process (ACTP) complex, indicates that this caudal could have belonged to a neosauropod. A second isolated middle-posterior caudal vertebra also shows some diagnostic features, despite the neural spine and neural arch not being preserved and the neurocentral sutures being unfused. The positioning of the neurocentral sutures on the anterior one third of the centrum indicates a middle caudal position, and the presence of faint ventrolateral crests, as well as a rhomboid anterior articulation surface, suggest neosauropod affinities. The presence of possible nutrient foramina are only tentative evidence of a neosauropod origin, as they are also found in Late Jurassic non-neosauropod eusauropods. As the caudals from the two other known sauropods from the Peterborough Oxford Clay, Cetiosauriscus stewarti and an indeterminate non-neosauropod eusauropod, do not show the features seen on either of the new elements described, both isolated caudals indicate a higher sauropod species diversity in the faunal assemblage than previously recognised. An exploratory phylogenetic analysis using characters from all four isolated elements supports a basal neosauropod placement for the anterior caudal, and a diplodocid origin for the middle caudal. The dorsal vertebrae are an unstable OTU, and therefore remain part of an indeterminate eusauropod of uncertain affinities. Together with Cetiosauriscus, and other material assigned to different sauropod groups, this study indicates the presence of a higher sauropod biodiversity in the Oxford Clay Formation than previously recognised. This study shows that it is still beneficial to examine isolated elements, as these may be indicators for higher species richness in deposits that are otherwise poor in terrestrial fauna.


2021 ◽  
Vol 325 (4) ◽  
pp. 447-456
Author(s):  
D.A. Gordeev ◽  
D.V. Korost ◽  
N.B. Ananjeva

Currently, more than 58 skeletal anomalies and pathologies are known in the recent Squamata reptiles. In this paper, eight pathologies of a complex nature are described in Agamidae and Lacertidae: Paralaudakia caucasia (Eichwald, 1831) and Lacerta agilis Linnaeus, 1758. Description of tail pathologies was carried out based on the analysis of X-ray images and on the results of computer microtomography. In the specimen of P. caucasia (ЗИН 19116.1) complete ablation of the caudal vertebra was revealed, which provoked the detachment of chevron and the proliferation of soft tissues. In some Agamidae, after pseudoautotomy, partial ablation of the caudal vertebra occurs to promote wound healing. Complete ablation of the distal caudal vertebra has not been previously reported in literature. In females of L. agilis, deformation of the right transverse process of the vertebra with “false bifurcation” without the formation of a cartilaginous tube (VOLSU 98.2), scoliosis, hematoma and callus on the cartilaginous tube were noted, as well as the absence of an autotomy plane in the postpygal vertebra (ZIN 31549). An unusual pathology in L. agilis (ZIN 31549) is the absence of an autotomy plane in the postpigal vertebra and of its anterior neural spine. The loss of the plane of autotomy during ontogeny is characteristic of some Iguanidae, but it has not been previously noted in Lacertidae. The described cases of anomalies expand the spectrum of known pathologies in reptiles.


2005 ◽  
Vol 3 (4) ◽  
pp. 597-605 ◽  
Author(s):  
John G. Lundberg

A fossil Weberian complex of a large pimelodid catfish from the middle Miocene La Venta fauna of central Colombia originally identified as Brachyplatystoma sp. is described as a new, extinct species. Brachyplatystoma promagdalena, new species, is diagnosed by three autapomorphic characters: fifth centrum with a massive midventral expansion containing deep cavities and heavy ridges; first and compound centra contribute to a pair of prominent anterolateral processes before the ventral ends of the ossa suspensoria; and compound centrum with an anteriorly concave low ridge crossing its ventral surface posterior to aortic canal foramen. Brachyplatystoma promagdalena is compared to modern congeneric species and placed in the subgenus Malacobagrus with B. filamentosum, B. capapretum and B. rousseauxii. This group is characterized by synapomorphies of the texture and form of the first vertebra; texture and form of the dorsal side of the fourth transverse process; and presence of a bony gas bladder platform on the ventral side of the fourth transverse process. Today Brachyplatystoma ranges widely across the lowland Orinoco and Amazon and some river basins of the Guianas. The genus does not occur west or north of the Andes or Venezuelan coastal ranges. The Miocene species of Brachyplatystoma signals the former large river and biotic connection between the paleo-Amazonas-Orinoco system and central Colombia, a region now drained by the río Magdalena. Other fossils of aquatic vertebrates from the La Venta fauna show this same biogeographic relationship.


Zootaxa ◽  
2008 ◽  
Vol 1931 (1) ◽  
pp. 57-67 ◽  
Author(s):  
ROGER B. J. BENSON

‘Megalosaurus’ hesperis from the Inferior Oolite (Bajocian, Middle Jurassic) of Dorset, UK is redescribed. Several features of ‘M.’ hesperis demonstrate that it is distinct from the lectotype dentary of Megalosaurus: an enlarged, subcircular third alveolus and subcylindrical, anteriorly inclined anterior dentary teeth; an anterior Meckelian foramen located almost directly anterior to the posterior Meckelian foramen; low interdental plates; and a prominent lip bounding the Meckelian groove ventrally, anterior to the Meckelian fossa. Therefore a new genus, Duriavenator, is erected to form the new combination D. hesperis. D. hesperis possesses two autapomorphies of the maxilla: a deep groove on dorsal surface of the jugal process containing numerous pneumatic foramina; and an array of small foramina in the ventral part of the articular surface for the premaxilla. Several features confirm the tetanuran affinities of D. hesperis: a prominent anterior process of the maxilla; the presence of band-like dental enamel wrinkles; the maxillary 'fenestra' is present but takes the form of an imperforate fossa (a spinosauroid synapomorphy); and the paradental groove is wide anteriorly, defining a distinct gap between the interdental plates and the medial wall of the dentary (a synapomorphy of Spinosauridae + Megalosauridae). Older records of tetanurans have been proposed, but most of these have been refuted and detailed re-examination of other early reports is warranted to establish the date of origin of this clade. An early Middle Jurassic origin of tetanurans is preferred.


Author(s):  
Fritz W. Huchzermeyer ◽  
Herman B. Groenewald ◽  
Jan G. Myburgh ◽  
Johan C.A. Steyl ◽  
Martina R. Crole

Humeri of farmed and wild Nile crocodiles (Crocodylus niloticus) collected during routine post-mortem examinations were boiled, cleaned and examined for lesions. Various degrees of gross bone and articular pathology were found. The lesions were situated predominantly at the proximal and distal epiphyseal and metaphyseal regions of the bone, where growth and bone remodelling occurs. In advanced cases partial collapse of the articular surface could be identified. From the collection of crocodile bones five particular cases are described. Because of the wide distribution of origin of the affected animals, nutritional or toxicological causes seem unlikely. One of the cases presented was associated with mycoplasmosis. These forms of crocodilian bone pathology need further investigation.


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